CHICAGO (AP) — A provision of Illinois' gay marriage law that let same-sex couples backdate marriages to the date of their civil unions is about to sunset.

June 1 marks the one-year anniversary of the state's gay marriage law taking effect. And a Wednesday statement from Cook County Clerk David Orr reminded couples the last day to backdate a marriage is Friday.

The law provided for backdating without paying a fee for one year. While the ability to backdate will end, Cook County will continue to waive the fee for couples converting civil unions to marriages.

The gay marriage law went into effect June 1, 2014, though Cook County began issuing marriage licenses to same-sex couples months earlier. More than 7,200 same-sex couples have been married in Cook County since Feb. 21, 2014.